Im running amsoil 15-40 synthetic. I drove to the grand canyon. When I got to the top and stopped in a parking lot my oil pressure (hot) went down to 10lbs and the engine actually started knocking (like a starving for oil knock). Im switching over to delo as my pressure was a full 10lbs higher with this oil.

Should I bring this up with the dealer?

Any and most all opinions are welcome here.

I would but they'll say something about your oilguard. If I remember correctly a little psi is sacrificed with the oilguard. In my old z71 I would change the oil when the pressure started to drop and presto full psi! Funny, it was right around 3k to 3.5k and that was with M1. When I switched to the Valvoline blend my pressure was constant all the time. No explanation, just an observation.

Perhaps your truck got real nervous when it saw the Grand Canyon? http://www.dieselplace.com/forum/smileys/Confused.gif

PC,


I think I might have had a experience like yours while towing from laramie to cheyenne wy, I noticed my oil pressure drop with a little knock, I had some smoke pouring out the same time, got to the top of the pass and everything seemed normal, another time driving to breckenridge up I-70 I had no pressure drop but a nasty valve like knock at idle, I shut down for an hour, and havent heard it since.

PC,


I haven't had mine drop that far but on long hot hauls with the trailer I have seen mine drop too. Every oil has done it. Last change I switched from stright M-1 to 6 Qts. of Delvac 1300 and 4 of M-1 trying to get a bit of both worlds. Didn't help. Just went back to straight M-1. Outside temp. seems to definately have an effect as well as mileage. I decided that my factory gauge just isn't that accurate because I see it fluctuate while pulling grades. As boost increases my oil pressure drops. So I decided to run the best oil I can and keep driving it like I stole it. Have never had a knock but it has gotten slightly noisier. I think if mine got low enough to knock I would probably take it in.

I've not seen any reduction in oil pressure with the OilGuard.

TC

well I changed my oil to delo and only got a 2lb boost in pressure. Since I installed the oilguard at the same time I switched to syn oil it has to be the oil guard thats dropping the pressure.

I will plug off one line tommorrow and see if it helps.

I doubt the oil guard would cause a drop at idle to 10# through a 40/1000 orifice. I would T off of the sender and check with a gauge.

I've not seen any reduction in oil pressure with the OilGuard. TC


Same here... I checked my oil pressure with a mechanical gauge before and after the OilGuard was installed and the pressure was unchanged. I'm currently running Delvac-1 and oil pressure is solid at 60psi on the OE gauge at 2000-2200 rpm.


http://www.dieselplace.com/forum/smileys/Geek.gif

I get 40-45 psi with delvac HOT.

I get 40-45 psi with delvac HOT.


PC,
Have you ever checked your oil pressure with a separate mechanical gauge plumbed into one of the pressurized ports on the full-flow adapter (as Tommy suggested)? The OEM electric gauges are notorious for being inaccurate.
http://www.dieselplace.com/forum/smileys/Geek.gif Edited by: jbplock

I also get 60-65 psi full hot with Delvac-1.

PC,


Mine also runs 60+ PSI hot. Definately think you need to at least check the accuracy of your stock gauge. I only get the lower pressure at idle.

Oil will get thinner when hot. Will have a lesser resistance to flow. Resistance is what causes the pressure.
Although not the likely problem in this case.

What kind of temperatures were you in, Problem Child?

I run the amzoil 15-40 & the Amzoil bypass, and with the engine warmed up good & oil temp around 215 degF I normally get around 18 - 20 psi oil pressure at idle (100 degF+ outside temps).


It runs around mid point or a needles width below on the stock pressure gauge running at 70 mph. (mid point is 40psi?? - can't remember?). I have never heard it knock at idle, but then again, I don't remember pressures below 18 - 20 psi. I have talked to about 4 or 5 owners that have seen pressures similar to mine, so I don't think this is out of the operating range for the D-Max.


I don't know that I would bring this up with the dealer, but I would really keep an eye on it! IIRC, I thought I heard somewhere on this forum that 13psi would not harm the engine at idle, but I can't recall where I heard this.


Hope this helps!
PDS

PC,


I would definatly bring this up with the dealer. It can't be instrumentation if it was knocking. Don't let the dealer tell you otherwise.


just my $.02

I had the same experience with amsoil on a long trip. My pressure did not drop as low as yours but it was noticably lower and with a knock. Now my tried and true amsoil beleiver friend told me not to worry that this was normal and "its better then conventional oil" Maybe.... well you can call me old fashion but I have always equated engine NOISE to engine wear so I went back to Delvac. Also - and this may have changed - but at that time I was told that Amsoil did not meet GM's recomendations. If that is/still true I don't know that i'd bring it up with them. Anyway I think the truth is that as long as you stick to a name brand you can't go wrong but as a wise man once said .....your engine oil is like your underware you want to use what makes you feel comfortable

Looks like there gonna be a big thing on oil coolers commin soonhttp://www.dieselplace.com/forum/smileys/Clap.gifand some one gonna be sellin them after they convince everyone they gotta have ithttp://www.dieselplace.com/forum/smileys/Ermm.gif


Genohttp://www.dieselplace.com/forum/smileys/Hug.gif

I run Amsoil 15W-40 Synthetic as well as the oil guard...no pressure drop. Is your bypass filter clogged?

PC, in no way do I intend this as a flame, so please don't take it that way.


But I have been reading oil pressure posts from you since I first found this forum. I've got to have thoughts and doubts about your oil pressure gauge. I think it's time you heeded the repeated advice to try another, known accurate gauge.


Get a name brand,such as Auto Meter, or Stewart Warner, mechanical gauge, hook it up and see what you get. Something just ain't kosher. I run Amsoil 5W-30 and don't have oil pressure anywhere near as low as you report. Got to believe you got a gauge problem. And as an old time racer and race car builder, I do know mthat not all oil pressure gauges are created equal.


Keep us informed,as we are all concerned, as we drive the same trucks.Edited by: dirty old man

Looks like there gonna be a big thing on oil coolers commin soonhttp://www.dieselplace.com/forum/smileys/Clap.gifand some one gonna be sellin them after they convince everyone they gotta have ithttp://www.dieselplace.com/forum/smileys/Ermm.gif


Genohttp://www.dieselplace.com/forum/smileys/Hug.gif





Geno, you're a bad boy. http://www.dieselplace.com/forum/smileys/HiHi.gif





PC, I would recommend verifying the gauge reading with a another gauge for a sanity check. If nothing else, it will give you piece of mind.


See if this helps.


I have found that I can have about a 5-7 psi difference between oil changes using the same oil and Baldwin B1441 filters. I would guess that the manufacturing tolerances in making the filters will cause that.


So, you might want to switch filters or brands and see if that helps.


I know aftermarket filters are not exactly like OEM spec filters but they come close. However, those little differences show up as oil pressure differences, slow pressure buildup, different flow rates, etc.


Hope that helps.

Dave


Check it out, he has been told numerious times to be sure his Guage is correct(how does he now the one he is checking with is correct) with a manual guage into the block. Ill be a bad boy if I can call you repeat.http://www.dieselplace.com/forum/smileys/Approve.gif Take the dam thing to a dealer if you dont now.


Genohttp://www.dieselplace.com/forum/smileys/Hug.gif

I know Geno.


PC is just worried about his truck.


I'm hoping to coax him to put his mind at ease.


Otherwise, Release The Hounds! http://www.dieselplace.com/forum/smileys/Big Smile.gif


PC, I know you hate to admit this, but Geno is right. Take your baby to the dealer and have them check the pressure. If you want to verify that the dealership won't screw you, find a friend with a gauge and check it yourself first. There are many things that can cause a pressure decrease in the oil system.


Sometimes it's as simple as a piece of dirt in the ball check valve that regulates the oil pressure.


Murphy has a strange way of screwing with you sometimes and it might be something unrelated to your choice of oil or filter.

I noticed that my pressure was less at idle when I used an STP oil filter. Won't do that again.